EP1651369B1 - Method and device for shaping and then lifting a workpiece - Google Patents

Description

The invention relates to a method according to the preamble of claim 1 and an apparatus for forming a workpiece according to the preamble of claim 20 (see for example DE-A-4 326 924).

For industrial forging of workpieces beating forming machines such as hammers and screw presses, in particular flywheel spindle presses known. Beating forming machines comprise a working area in which two tools, generally rectilinear, are movable relative to each other. The workpiece is placed between the two tools and then reshaped by the impact or impact energy as the tools strike the workpiece and the forming energy caused thereby.

According to VDI-Encyclopedia "Production Technology Process Engineering"; Publisher Prof. Dr. med. Hiersig, VDI-Verlag, 1995, pages 1107 to 1113 divided forging hammers in Schabottehämmer, these in turn divided into hammers and overhead hammers, and counterheast hammers. A scraper hammer comprises a scraper (or: a carrier, an anvil) as a tool fixed relative to the workpiece, and a striker or, in short, bears, relative to the workpiece and scraper, usually a vertical, moving tool. A counter-hammer has two against each other and in each case relative to the ground or the hammer frame, vertically or horizontally, moving striker on. The drives for the bears of blacksmith hammers are generally hydraulic or pneumatic. In the actual forming or working process, the hammer frame and the hammer drives of a forging hammer are relieved of the forming force, so that forging hammers are not overloaded. In the case of screw presses, the moving tool is usually called a ram. The plunger is moved rectilinearly to the stationary tool by a spindle. The drive of the spindle and thus of the plunger via a drive motor and / or flywheel as energy storage. Before hitting the workpiece located on the stationary tool, the spindle or the ram is decoupled from the drive and the kinetic energy given to the ram is (partly) converted into transformation energy ( VDI-Lexikon, loc. cit. )

It is in accordance with VDI encyclopedia "production technology process technology"; Publisher Prof. Dr. med. Hiersig, VDI-Verlag, 1995, pages 848 and 849 and 1214, known to use for automated handling of workpieces during pressing or forging handling equipment such as manipulators and industrial robots having grippers for gripping and temporarily holding the workpieces and insert the workpieces in the forging machine or remove from this. Manipulators are manually controlled moving devices with usually specific process-specific controls or programming. Industrial robots are universally applicable automatic movement machines with a sufficient number of degrees of freedom of movement, realized by a corresponding number (5 to 6) of axes of motion, and a freely programmable controller for the realization of virtually any movement trajectories of the workpiece within the movable or reachable by the industrial robot space area.

A problem with the use of such handling devices are the high impact forces in a beating forming machine, which can significantly burden and damage the handling device during forming blow when the handling device holds the workpiece when the bear or tappet blows. To solve this problem, handling devices have been proposed in DE 42 20 796 A1 and DE 100 60 709 A1 , which can be made yielding during the impact for damping the impact impacts and vibrations transmitted from the workpiece to the drive and rigid in the transport of the workpiece be put.

In practice, an automation of the handling of workpieces in forging processes with hitting forming machines has not been able to prevail decisively. Rather, in practice, the workpiece is still held manually by a human with a gripping tool in the forging hammer, since appropriately trained people master the correct handling of the workpiece upon impact of the bear with the percussion tool. After reversing the bear, the human raises the workpiece and places it before re-encountering the bear at the next stroke back into the tool or equal in a storage device from.

The invention is based on the object of specifying a method and a device for forming a workpiece, in which the lifting of the workpiece from the tool is automated after a forming process.

This object is achieved according to the invention by a method having the features of claim 1 and a device having the features of claim 20.

1. a) Positionieren des Werkstücks in eine Umformlage auf einem ersten von wenigstens zwei Werkzeugen der Umformmaschine (Positionierschritt),
2. b) Bewegung der Werkzeuge der Umformmaschine relativ aufeinander zu,
3. c) Umformen des Werkstücks zwischen den Werkzeugen, insbesondere in seiner Umformlage auf dem ersten Werkzeug (Umformschritt),
4. d) anschließende Bewegung der Werkzeuge relativ voneinander weg,
5. e) Erfassen oder Bestimmen eines Auslösezeitpunktes, zu dem, während der Relativbewegung der Werkzeuge aufeinander zu, die Relativposition der Werkzeuge eine vorgegebene Referenzposition einnimmt oder erreicht hat,
6. f) Bestimmen oder Auswählen eines Abhebezeitpunktes in Abhängigkeit oder als Funktion des Auslösezeitpunktes,
7. g) Abheben (oder: Einleiten oder Starten) einer Abhebebewegung des Werkstücks von dem ersten Werkzeug durch wenigstens ein Handhabungsgerät zu dem Abhebezeitpunkt.

The method according to claim 1 is suitable for forming, in particular forging, at least one workpiece and determines and comprises the following method steps:

1. a) positioning the workpiece in a forming position on a first of at least two tools of the forming machine (positioning step),
2. b) movement of the tools of the forming machine relative to each other,
3. c) forming the workpiece between the tools, in particular in its forming position on the first tool (forming step),
4. d) subsequent movement of the tools relative to each other away,
5. e) detecting or determining a triggering time at which, during the relative movement of the tools towards each other, the relative position of the tools assumes or has reached a predetermined reference position,
6. f) determining or selecting a lifting time depending on or as a function of the triggering time,
7. g) lifting (or: initiating or starting) a lifting movement of the workpiece from the first tool by at least one handling device to the lifting time.

1. a) wenigstens eine Umformmaschine mit wenigstens zwei relativ aufeinander zu und voneinander weg bewegbaren Werkzeugen zum Umformen eines auf einem ersten der Werkzeuge in einer vorgegebenen oder vorgebbaren Umformlage positionierten oder positionierbaren Werkstücks zwischen den Verkzeugen,
2. b) wenigstens eine Positionserfassungseinrichtung zum Erfassen eines Auslösezeitpunktes, zu dem, während der Relativbewegung der Werkzeuge aufeinander zu, die Relativposition der Werkzeuge eine vorgegebene oder vorgebbare Referenzposition einnimmt oder erreicht hat,
3. c) wenigstens ein Handhabungsgerät zum Handhaben des Werkstücks,
4. d) wenigstens eine Kontrolleinrichtung zum Steuern oder Regeln der Bewegungen und Positionen des oder der Handhabungsgeräte(s),
5. e) wobei die Kontrolleinrichtung derart ausgebildet ist, dass sie abhängig von dem Auslösezeitpunkt einen Abhebezeitpunkt bestimmt und das wenigstens eine Handhabungsgerät so ansteuert, dass das wenigstens eine Handhabungsgerät das Werkstück zu dem Abhebezeitpunkt von dem ersten Werkzeug abzuheben beginnt.

The device according to claim 20 is for forming, in particular forging, at least one workpiece and in particular for use in a method according to the invention or for carrying out a method according to the invention is suitable and intended and comprises

1. a) at least one forming machine with at least two relatively movable towards and away from each other tools for forming a positioned on a first of the tools in a predetermined or predetermined forming position or positionable workpiece between the Verkzeugen,
2. b) at least one position detection device for detecting a triggering time at which, during the relative movement of the tools towards each other, the relative position of the tools assumes or has reached a predetermined or specifiable reference position,
3. c) at least one handling device for handling the workpiece,
4. d) at least one control device for controlling or regulating the movements and positions of the handling device (s),
5. e) wherein the control device is designed such that it determines depending on the triggering time a lifting time and controls the at least one handling device so that the at least one handling device starts to lift the workpiece at the lifting time of the first tool.

Of course, the movement of the tools relative to each other when hitting the forming machine involves both the case of only one (the first) of the two tools moving relative to the ground or machine frame or other external reference frame and the other (the second) tool moving to that external one System remains stationary, for example in a top hammer or a monkey or a screw press, as well as the case that both tools move relative to the external reference system, for example in a counter-impact hammer. The forming position of the workpiece refers to its absolute and adjustable geometric position in space with respect to an external coordinate system. Automatic means that at least when lifting itself no human intervention or detention of the workpiece is required, but this is done automatically by the handling devices (or: moving machines), generally under the control of a control device.

The invention is based on the consideration that the at least one handling device only lifts the workpiece from the first tool when the tools have reached a predetermined or predefinable position, referred to here as the reference position. In particular, this allows precise control of the handling device such that the workpiece has already been completely reshaped at the time of lifting between the tools, ie the lifting time after the forming time at which the forming of the workpiece between the tools is complete, and / or that the tools move (again) relatively away from each other, so the Abhebezeitpunkt after the reversal time of the tools, to which the direction of relative movement of the tools is reversed to each other, is located. A particular advantage of the control of the handling device as a function of the tool position according to the invention is that the lifting time can be set very close to the forming or reversing time, whereby tool contact times and / or cycle times can be shortened.

Advantageous embodiments and further developments of the method and the apparatus for forming a workpiece according to the invention will become apparent from the dependent claim 1 and claim 20 respectively claims.

The lifting time for the at least one handling device in a first advantageous embodiment is a predetermined or predefinable time difference after the forming time or after the reversal time. This time difference between Abhebezeitpunkt and Umformzeitpunkt or reversal time is between 0 ms and a maximum of 300 ms and / or a maximum of 3/4 of the time for the movement apart of the tools, in particular between 0 ms and a maximum of 100 ms and / or a maximum of 1/4 of the time for the movement apart of the tools, preferably between 0 ms and a maximum of 50 ms and / or a maximum of 1/8 of the time for the movement apart of the tools, and / or is dependent on a predetermined Werkzeugberührzeit.

In a preferred embodiment, at least one control device is provided, the movements of the at least one handling device controls and determines depending on the triggering time the Abhebezeitpunkt and initiates a lift-off or Abheberoutewerk the handling device to the determined Abhebezeitpunkt.

The control device sends a start signal to the at least one handling device, in particular at a start time, and the at least one handling device starts a lift-off movement upon receipt of this start signal and lifts the workpiece at the lift-off time. In this embodiment, the handling device therefore to a certain degree itself has possibilities for signal processing and the control is done via signals.

In general, at least one position detection device is provided, which at the release time, when the relative position of the tools reaches the reference position, sends a trigger signal to the control device, and wherein the control device determines the lift-off time depending on the input time of the trigger signal.

The position detection device may comprise a position switch associated with the reference position or arranged at the reference position, which changes its switching state when actuated by one of the two tools, wherein a switching state change of the position switch is used as a trigger signal or trip time.

However, the at least one position detection device can also measure the relative position of the two tools with each other continuously or continuously or at specific measuring points and deliver to the control device a corresponding position measuring signal or a corresponding position measured value. The control device then compares the position measurement signal or the position measurement value with a reference signal or reference value corresponding to the reference position and evaluates a determined coincidence of the position measurement signal with the reference signal or the position measurement value with the reference value as the triggering time and determines therefrom the release time.

In a particularly advantageous embodiment, the control device determines the lift-off time from the triggering time by adding or executing a predetermined delay time at the triggering time, for example by means of a digital counter or a clock. In particular, the control device can determine the starting time for the start signal by running or adding the predetermined delay time to the triggering time, wherein the lift-off time from the start time in a unique manner, generally by adding the signal delay time and processing time of the start signal for the handling device results. The delay time is generally dependent on the course of at least one relative movement variable in the relative movement of the tools towards each other and / or depending on a set or adjustable forming energy.

It is also possible in all embodiments, although unusual in today's technology, without a signal transmission and evaluation provide immediate control or regulation of the handling devices, for example via components or actuators, depending on the relative position of the tools the control current for drive (e ) of the handling device directly. For example, as soon as the relative position of the tools reaches the reference position, the position switch could immediately trigger one or more switch contacts that switch on or through a control current for the manipulator, or electrical or electro-mechanical delay elements or switches, e.g. Bimetal relay, components with hysteresis or the like may be provided.

• zeitlicher Verlauf der Relativbewegung der beiden Werkzeuge
• Wert der Umformenergie für das Umformen des Werkstücks oder einer mit der Umformenergie eindeutig korrelierte Größe, insbesondere wenn dieser Wert auf einen von wenigstens zwei verschiedenen Werten einstellbar ist
• die Summe der für die Ermittlung des Abhebezeitpunktes aus dem Auslösezeitpunkt mindestens erforderlichen Signal- oder Datenlaufzeiten und Signal- oder Datenverarbeitungszeiten ist kleiner als der Zeitabstand aus Abhebezeitpunkt und Auslösezeitpunkt.

The reference position for the tools is preferably selected depending on one or more of the following process variables or conditions:

• Time course of the relative movement of the two tools
• Value of the forming energy for reshaping the workpiece or a quantity uniquely correlated with the forming energy, in particular if this value can be set to one of at least two different values
• the sum of the minimum signal or data delay times and signal or data processing times required for determining the lift-off time from the triggering time is less than the time interval from the lift-off time and the triggering time.

The reference position may in particular correspond to the most distant relative position of the tools, in particular the so-called TDC (upper dead center) of the forming machine, but is usually between the farthest relative position, in particular TDC, and the next relative position, the impact position, in particular the UT (bottom dead center) of the forming machine.

In a particular embodiment, a self-learning or adaptive system is provided in which lift-off time is automatically learned or adjusted by determining the relative position of the tools at the lift-off time in one or more forming steps (or tool movements) and adjusting the lift-off time to a desired value, in particular by adjusting the delay time after the triggering time or by adjusting the reference position. As a result, in particular the lifting time point can be placed as close as possible to the time of reversal of the tools and thus the time sequence can be optimized.

The at least one handling device, which lifts the workpiece, preferably also positions the workpiece in its forming position on the first tool and / or holds the workpiece during the forming between the tools in its forming position. However, it is also possible to use at least some of the time or part of different handling devices for the different manipulations.

Preferably, at least during the impingement of the tool (s) of the forming machine during the forming step, the workpiece is held or gripped at at least two points, each with a handling device. This has the advantage that the workpiece is fixed at two points when the tool or tools (s) strike and thus more reliably prevents them from jumping or slipping in the tools can be. Another advantage is that kinking of a longer workpiece on one side can be prevented because the handling devices can fix the workpiece on both sides and stabilize the forming impact.

In an advantageous embodiment, the workpiece is also handled, or at least when lifting at least two handling devices, in particular the same handling devices as during holding during the forming.

The movements and positions of the handling devices are controlled or regulated automatically and coordinated. When controlling the handling device (s), the movement takes place in accordance with a predefined or predeterminable movement sequence or movement profile or a corresponding stored control program (no feedback "open loop control"), while the movements of the handling devices are detected during the measurement and predetermined movements ( Reference variables of the movement) are adjusted or regulated (feedback, "closed-loop-control"). Matched to each other are the movements or positions of the two handling devices in order to be able to handle the workpiece exactly. So there is a kinematic coupling between the two handling devices provided when handling the workpiece during its transformation.

In an advantageous embodiment, the two handling devices are moved synchronously and / or along mutually substantially constantly spaced trajectories and / or at substantially the same speed, at least in a part of the manipulations of the workpiece by two handling devices

The control device controls or regulates the two handling devices, in particular their respective drive devices, in one embodiment according to a master-slave control principle, wherein a serving as a slave handling device follows a master serving as a handling device in the movements.

In an alternative preferred embodiment, the control device controls the two handling devices, in particular their respective drive means, independently of one another, with respective control processes adapted to each other.

In general, each handling device or its point of attack on the workpiece moves during a movement and / or handling of the workpiece along a previously determined trajectory with a predetermined velocity profile and / or trailing successive trajectory points at regular time intervals.

The associated trajectory of the handling device or its point of application on the workpiece is preferably learned in advance, but can also be calculated. In a particular embodiment, (only) the trajectory of at least two handling devices or its point of application is taught on the workpiece and the trajectory of the at least one further handling device or its point of attack on the workpiece is calculated in advance from the learned trajectory of the first handling device and stored or calculated in real time , When teaching the trajectory of a handling device or its point of attack on the workpiece, the associated trajectory is generally traversed, and at regular time intervals, the trajectory points are sequentially recorded and stored. The speed course during training is preferably predetermined according to the later speed course in the process. With any velocity course during teach-in, the actual speed profile during operation can also be considered later and new trajectory points can be calculated and stored. The handling device or its point of application on the workpiece during the movement and / or handling of the workpiece in each case follows the trajectory points stored during training, possibly after speed correction, at the same time intervals and in the same sequence as during training.

When handling the forming machine, the two handling devices are preferably located on opposite sides of the work area or the tools of the forming machine.

In one embodiment, in which the workpiece is formed in at least two forming steps between the same tools, in a variant after a forming step, the workpiece is lifted from the at least one handling device from the first tool and then back to the first tool in the forming position for the subsequent forming step is positioned.

In another variant, the workpiece is lifted by the at least one handling device from the first tool after a forming step and then positioned on the first tool in another tool area or on or in another tool in the forming position for the subsequent forming step. In a further variant, after the forming step or after the last forming step, the workpiece is transported by the at least one handling device after it has been lifted off the tool or tool area to a depositing device and deposited there.

In particular, between two forming steps, in a preferred embodiment, by means of at least one blower, scale material is now blown out below the lifted workpiece and / or from the tool. This step is also called airing. The blower is preferably, in particular by the control device, so controlled that the switch-on or commissioning or the pre-fan is determined depending on the triggering time (analogous to the lifting movement of the handling device) and preferably after the lifting time.

1. a) wenigstens eine Greifeinrichtung mit wenigstens zwei relativ zueinander bewegbaren Greifelementen zum Greifen des Werkstücks,
2. b) wenigstens eine Trägereinrichtung, an der die Greifeinrichtung befestigt oder befestigbar ist und
3. c) wenigstens eine Transporteinrichtung zum Transportieren der Trägereinrichtung mit der Greifeinrichtung auf.

In an advantageous embodiment of the device has each handling device

1. a) at least one gripping device with at least two gripping elements movable relative to one another for gripping the workpiece,
2. b) at least one carrier device to which the gripping device is attached or attachable and
3. c) at least one transport device for transporting the carrier device with the gripping device.

The device is now preferably further developed in that a flexible connection between the carrier device and the transport device in a flexible state at least partially absorbs shocks or vibrations transmitted from the workpiece to the handling device during the forming process and thus protects the transport device from these mechanical loads; and that a rigid connection or position of support means and transport means in a rigid state, however, when handling the workpiece during transport or during rotation or pivoting is used before or after forming steps.

Preferred applications of the invention are when using a forging or a screw press or a crank press as a forming machine and / or for forging and / or cold forming with a forming temperature typically in the range of room temperature (21 ° C), for warm forging, typically between 550 ° C and 750 ° C, or for hot forming, typically above 900 ° C, and / or for forming workpieces of malleable metals and metal alloys, especially ferrous materials such as steels and non-ferrous metals such as magnesium, aluminum, titanium, copper, nickel and alloys thereof , In general, the tools of the forming machine are forming dies for bonded forming of the workpiece.

FIG 1

eine Vorrichtung mit zwei Handhabungsgeräten beim Ergreifen eines Werkstücks in einer Seitenansicht,

FIG 2

die Vorrichtung gemäß FIG 1, bei der die zwei Handhabungsgeräte das in eine Umformmaschine gelegte Werkstück halten, in einer Seitenansicht,

FIG 3

die Vorrichtung gemäß FIG 1 oder FIG 2, bei der die zwei Handhabungsgeräte das in der Umformmaschine befindliche Werkstück nach dem Umformschlag anheben oder lüften, in einer Seitenansicht,

FIG 4

eine Vorrichtung zum Umformen eines Werkstücks mit zwei Handhabungsgeräten, die das Werkstück entlang vorgegebener Bewegungsbahnen handhaben, in einer schematischen perspektivischen Ansicht und

FIG 5

eine Vorrichtung zum Umformen eines Werkstücks mit zwei Handhabungsgeräten bei einer Handhabung des Werkstücks in einer Draufsicht

jeweils schematisch dargestellt sind. Einander entsprechende Größen und Teile sind in den FIG 1 bis 5 mit entsprechenden Bezugszeichen versehen.The invention will be explained below with reference to exemplary embodiments. Reference is made to the drawing, in whose

FIG. 1

a device with two handling devices when gripping a workpiece in a side view,

FIG. 2

1 the device according to FIG. 1, in which the two handling devices hold the workpiece placed in a forming machine, in a side view,

FIG. 3

the device according to FIG. 1 or FIG. 2, in which the two handling devices lift or ventilate the workpiece located in the forming machine after the forming knock, in a side view,

FIG. 4

a device for forming a workpiece with two handling devices, the workpiece along predetermined paths of movement handle, in a schematic perspective view and

FIG. 5

a device for forming a workpiece with two handling devices in a handling of the workpiece in a plan view

are each shown schematically. Corresponding sizes and parts are provided in FIGS 1 to 5 with corresponding reference numerals.

There are a first handling device with 2 and a second handling device designated 2 '. Each of the handling devices 2 and 2 'can be designed as a manipulator or robot. In the exemplary embodiments illustrated in FIGS. 1 to 5, the two handling devices 2 and 2 'are substantially identical in construction and each comprise a gripping device (or gripping tongs) 3 or 3', a carrier shaft 4 or 4 ', a support device (or: Starrstellungseinrichtung) 5 or 5 ', a bearing part 6 or 6', a flexible element 7 or 7 ', a rotary actuator (or: rotary drive) 8 and 8', a joint 9 or 9 ', an actuator 11 and 11 'and a transport device 16 or 16'.

Each gripping device 3 or 3 'comprises two gripping levers 32 and 33 or 32' and 33 'each having an associated gripping jaw (or: gripping element, jaw jaw) 30, 31, 30' and 31 ', which by means of the actuating device 11 or 11 'to one another in a pivot bearing 34 or 34' are pivotable for opening and closing the gripping device 3 or 3 '. The actuating device 11 or 11 'engages in an attack bearing 35 or 35' on the gripping lever 33 or 33 'and is in a pivot bearing 14 or 14' pivotally mounted on the intermediate part 6 and 6 '. The gripping lever 32 or 32 'of the gripping device 3 or 3' is connected via the carrier shaft 4 or 4 'to the intermediate part 6 or 6' coaxially along an axis M. Between the intermediate part 6 and 6 'and connected to the hinge 9 and 9' along a second axis N pivot drive 8 and 8 ', the flexible element 7 and 7' is arranged, and via a respective flange with the intermediate part 60 and 60 'and the pivot drive 8 and 8' is connected and made of an elastic material, preferably an elastomer. In the flexible element 7 or 7 'are now the front unit of the handling device 2 or 2', namely the gripping device 3 or 3 ', the carrier shaft 4 or 4 'and the bearing part 6 or 6' and the actuating device 11 or 11 ', on the one hand and the rear unit of the handling device 2 or 2', namely the pivot drive 8 and 8 'and the hinge 9 and 9 respectively 'And the transport means 16 and 16', and thus also their axes M and N to each other swivel or tilt.

The support means 5 and 5 'of the handling devices 2 and 2' according to FIGS. 1 and 2 comprises a longitudinal connecting rod 53 or 53 ', on which a respectively transversely upwardly extending first fastening part 51 or 51' for connecting the connecting rod 53 or 53 'with the pivot drive 8 and 8' and further back a transversely extending second fastening part 52 and 52 'for connection to the hinge 9 and 9' and in the front region an upwardly projecting support member 50 and 50 'with an incision or support bearing (or: a shaft seat) for fixing or supporting the support shaft 4 and 4 'are arranged. FIGS. 1 and 2 illustrate u.a. Also, the operation of the support means 5 and 5 'and the flexible element 7 and 7' of the handling devices 2 and 2 '.

In the state shown in FIG. 1, the handling devices 2 and 2 'with open gripping devices 3 and 3' move from both sides in the direction of the illustrated arrows towards a workpiece 10 which is provided on a supply device, for example a conveyor belt 41. The axes M and N and M 'and N' are coaxial with each other and directed horizontally, ie perpendicular to the gravitational force G, the flexible element 7 or 7 'is substantially undeformed and the connecting rod 53 or 53' is parallel to the axes M and N or M 'and N' and their support member 50 and 50 'supports the carrier shaft 4 and 4' and thus the associated gripping device 3 and 3 'from. The support device 5 or 5 'thus represents a mechanical bridging over the flexible element 7 or 7' and thus eliminates in the position shown in FIG 1, the flexibility of the handling device 2 or 2 'in the flexible element 7 or 7' at least in the spatial direction of gravity G and in the downward lateral directions between the gravity G and the horizontal direction. The rigid connection is maintained solely by the weight of the parts of the handling device 2 and 2 '. Upon reaching the workpiece 10, the gripping means 3 and 3 'are closed and thus the workpiece 10 taken at its ends 10A and 10B and transported by the transport means 16 and 16 'to a forming machine and placed there in the forming position for forming on a tool. In this case, the handling device 2 or 2 'is held in a rigid state via the support device 5 or 5'.

2 shows the workpiece 10 in the mounted state on the surface 22 of the lower tool or die 12 of a forging hammer as a preferred example of a forming machine. By raising the rear units of the handling devices 2 and 2 ', ie inclining the central axis N or N' by the inclination angle a or a 'with respect to the central axis M or M' of the front unit about the flexible element 7 or 7 ', is the support means 5 and 5 'brought out of engagement with the support shaft 4 and 4', as the support member 50 and 50 'sufficiently away from the support shaft 4 and 4'. In the tilting movement about the angle α or α 'while the die 12 serves over the workpiece 10 as an abutment. The handling devices 2 and 2 'are thus in FIG. 2 in a flexible or non-rigid state. Now, if an upper tool or impact tool 13 strikes the workpiece 10 on the beater 15 of the forging hammer in the direction of impact or forward direction VR, resulting shock and vibration loads are damped by the elastic elements 7 and 7 'and largely by the transport device 16 or 16 'and the pivot drive 8 and 8' decoupled, so that these drive devices are protected from overloading.

Both in the rigid state and in the flexible state of the handling devices 2 and 2 'can be rotated in the illustrated embodiment, the workpiece 10 before placing on the die 12, in particular about an extending through the workpiece 10 axis of rotation, for example, its longitudinal axis. For such a rotary or pivoting movement, the gripping means 3 and 3 'are pivoted with the gripped workpiece 10 by the desired pivot angle in the same direction of rotation and with the same rotational or angular speed. For this purpose, a rotational movement of an output shaft of a drive motor of the rotary actuator 8 or 8 'is arranged, if necessary via a transmission and via a drive flange and the flexible element 7 or 7' and via a connecting flange in turn on the Intermediate part 6 or 6 'is transmitted and from there to the carrier shaft 4 or 4' and finally the gripping device 3 or 3 '. Such pivotal movements occur, for example, during bending of a workpiece in a first forging or forging step and subsequent flat forming or forging. The rotation of the gripping means 3 and 3 'may be omitted if rotation is not desired.

FIG. 3 shows, starting from FIG. 2, the situation shortly after the impact tool 13 strikes the workpiece 10 and the surrounding areas of the tool 12. The impact tool 13 is returned to the tool 12 by the recoil and optionally by a drive directed upward movement in a reverse direction RR.

Now, the workpiece 10 is raised or released by the tool 12 by a distance d. This lifting or lifting movement of the two handling devices 2 and 2 'and of the workpiece 10 held by them thus follows the striking tool 13, which moves upward after the forming impact, in the same direction as the backward direction RR. The handling devices 2 and 2 'can remain in the flexible position, as shown in FIG 3, or be made rigid before the lifting movement as in FIG 1. During or after the release movement Zundermaterial from the lower tool 12 by means of, not shown Blower blown out. The lifting or lifting also shortens the contact time of the workpiece 10 with the lower tool 12th

After the lifting or lifting process, either the workpiece 10 can now be placed again on the die 12 or on another die or another engraving of the die 12 and be re-formed with the striking tool 13 or another striking tool.

But it can also be completed, the forming process and the workpiece 10 is moved out of the illustrated in FIG 3 position of the two handling devices 2 and 2 'from the work area of the forming machine between the two tools 12 and 13 and transported to a storage device. 4 shows such a handling of the workpiece 10 after forming. The trajectories or trajectories the two handling devices 2 and 2 'are denoted by S and S', the directions of movement marked with arrows.

The two handling devices 2 and 2 'are each started at a lift-off time t1 from a starting position S (t1) and S' (t1) according to FIG 4, in which they the workpiece 10, with the gripping means 3 and 3 'at the respective end 10A or 10B gripping, hold on the die 12 of the forming machine resting. Now, both handling devices 2 and 2 'initially move upward, so that the workpiece 10 is lifted off the surface 22 of the die 12. The uppermost point of this lift-off movement at a time tk> t1 is denoted by S (tk) or S '(tk).

Following the lift-off movement, the handling devices 2 and 2 'now transport the workpiece 10 along the trajectories S and S', which now extend horizontally in the illustrated example, and finally arrive at a deposit time tn at the positions S (tn) and S '(tn). the workpiece 10 on a depositing device 42, which includes, for example, a conveyor belt for transporting the finished forged workpiece 10. The two trajectories S and S 'of the handling devices 2 and 2' are generally parallel to each other and the handling devices 2 and 2 'are moved synchronously with each other. As a result, the workpiece 10 is moved substantially only translationally and not rotationally. At any given time tj, the difference vector A = S '(tj) -S (tj) is always the same.

According to the invention, the lifting movement of the workpiece 10 with the handling devices 2 and 2 'according to FIGS. 2 to 4 is initiated or started depending on the position or the position of the striking tool 13. The position of the impact tool 13 simultaneously corresponds to the relative position of the two tools 12 and 13 to each other, since the die 12 is stationary. The impact tool 13 moves in its stroke and return movement, which is also referred to as stroke linearly between an upper end point x0, which is also referred to as top dead center (TDC), and a lower end point xE, which is also referred to as bottom dead center (UT) referred to as.

At a predetermined reference position xR with x0 <xR <xE a position sensor 25 is arranged, which provides a position signal P at its output. The position signal P is a measure of whether and when the impact tool 13 reaches the reference position xR, and then corresponds to a reference position signal PR.

The position sensor 25 may be formed as a kind of position switch taking two values or states, namely a value or state when the position x of the striking tool 13 does not correspond to the reference position xR, and a second value or state, namely a reference position value or reference position state PR if x equals xR. For this purpose, a non-contact position sensor or position switch is usually used, which responds to a localized release point on the impact tool 13, for example, a magnetic position sensor, which responds to a mark of magnetic material on the impact tool 13.

In another embodiment, the position sensor 25 can also detect and determine the position x of the striking tool 13 over the entire distance from x0 to xE and back continuously or quasi-continuously in individual measuring points xi. The position signal P is then an injective or bijective function of the position x or xi with P (xR) = PR. For this purpose, for example, on the impact tool 13, a strip extending parallel to the path or coordinate direction x or a similarly designed marking can be provided, which enables incremental position detection by a pattern which changes in small increments or steps.

The aforementioned position detection systems are known per se and therefore require no further explanation. The position sensor 25 may in particular be an optical, inductive or magnetic field sensor.

The position signal P of the position sensor 25 is supplied to a control device 43. The control device 43 decides on the basis of the position signal P whether it and when it initiates a lift-off movement of the handling devices 2 and 2 '. For this purpose, the control device 43 is in operative connection with the handling devices 2 and 2 'and controls the handling devices 2 and 2 'by means of associated control signals C and C'. As soon as the impact tool 13 reaches the reference position xR in the downward movement, ie in the direction of the forward direction VR, the position sensor 25 sends a corresponding reference position signal P = PR to the control device 43. The control device 43 adopts the time of the input of the reference position signal PR as a triggering time tR a spin-off routine in the control device 43 is initiated. According to an algorithm or calculation method stored in the control device 43, a start time is now determined at which the start signals C and C 'are sent to the handling devices 2 and 2'. After receiving the synchronous start signals C and C 'by the two handling devices 2 and 2', the drive systems of the handling devices 2 and 2 ', in particular the transport devices 16 and 16', so controlled that at a lift-off time t1 according to FIG 4, the lifting movement of the workpiece 10 begins and the handling devices 2 and 2 'move upwards along their trajectories S and S'.

The Abhebezeitpunkt t1 is due to a systemic reaction time and the signal propagation times of the start signals C and C 'and the signal processing times in the handling devices 2 and 2' later than the start time in the control device 43 and by a further time difference, by the computing times in the control device 43 and the signal propagation times for the position signal P is determined later than the time at which the impact tool 13 had reached the reference position xR. Since these delay times in the system can be predetermined or within predetermined limits, the lift-off time t1 can be set very close to the time of reversal of the percussion tool 13 to which the percussion tool 13 reverses its direction from the forward direction VR to the reverse direction RR. This initiation of the lifting movement of the handling devices 2 and 2 'at the moment of reversing or shortly afterwards means a short tool contact time, which in turn increases tool life and productivity. The occurring delay times due to the signal transmission times and computer times are compensated by the starting of the handling devices 2 and 2 'during the downward movement of the impact tool 13.

For determining the starting time at which the start signals C and C 'are sent from the control device 43 to the handling devices 2 and 2', a delay time is preferably allowed to pass in the control device 43 after receiving the reference position signal PR of the position sensor 25, for example by means of a digital Counter or a built-in clock. After the delay time, the start signal C or C 'is sent. Each associated forming energy of the forming machine is assigned an associated delay time. This relationship between set transformation energy and delay time can be established by means of a mathematical function or a value table in the control device 43.

When using a continuous position detection system, in which the position x between x0 and xE is known at each point, a separate reference position xR for the impact tool 13 can be assigned for each set forming energy of the forming machine and thus an individual starting point for the handling devices 2 and 2 ' be assigned. This relation between reference position xR and starting point for the handling device can also be established by means of a mathematical function or a table of values in the control device 43.

In addition to the position x or xi or xR, the speed dx / dt of the impact tool 13 in the control device 43 can also be calculated, for example by numerical differentiation on the basis of the obtained values xi or x for the position of the impact tool 13. This makes it possible to control any speed to assign a separate starting point for the handling devices 2 and 2 '. This relationship between the starting point for the handling devices 2 and 2 'and the speed of the striking tool 13 can also be established by means of a mathematical function or a table of values in the control device 43.

In a typical operation of a forming device according to the invention, for example, two different forming energies are used on the forming machine. From each of the two adjustable forming energies results depending on the mathematical function or the value table by means of the control device 43, a starting time for the handling devices 2 and 2 '. In a position detection system in the forming machine, the set point is compared in the control device 43 as a calculated starting point with the actual value or actual position of the striking tool 13. From the comparison of the actual value and the setpoint value, the control device 43 forms the starting signal C or C 'for the handling devices 2 and 2' when the setpoint value is reached.

The tools 12 and 13 are usually forming tools, so-called dies with customized according to the desired shape of the workpiece engraving. The handling devices 2 and 2 'generally hold the workpiece 10 throughout the forging cycle and perform all of the handling movements necessary for the forging process jointly and synchronously. The common and synchronous driving of the two handling devices 2 and 2 'is achieved via an electrical coupling between the two handling devices 2 and 2', wherein the coupling via the master-slave operation of electric drives or by the simultaneous start of independently operating drives is reached. The movements of the handling devices 2 and 2 'and thus the handling movements for the workpiece 10 are usually learned in advance in a conventional manner.

The control device 43 can additionally perform the complete signal exchange. In general, the control device operates by means of at least one digital processor, in particular a microprocessor or a digital signal processor, and corresponding memory in which the sequence programs, control algorithms and data for the movements are stored. For a master-slave operation known per se master-slave control units can be used. For independently operating drives, the same distances and speeds as well as error feedback and error responses between the independent drives are provided in order to ensure an exact and in case of failure safe operation.

5 shows another embodiment of a device for handling a workpiece during a forging process. This device again comprises two handling devices 2 and 2 'with respective gripping devices 3 and 3 ', which are shown schematically as industrial robots. The two handling devices 2 and 2 'receive a workpiece 10 from a supply device 41, for example a feed conveyor belt or another automated feed device, and place the workpiece in a first engraving 17 of a tool 12 of a striking die-forming machine. The counter tool or impact tool of this die-forming machine is not shown and would be in the illustrated plan above the plane of the drawing. During or at the end of the handling movement or transfer movement of the supply device 41 in the first engraving 17 of the tool 12, the impact tool of the forming machine is triggered. After the shock release, a new sequence for the further handling of the workpiece 10 is initiated by a time during or at the end of the impact movement of the impact tool. First, the workpiece 10 is fixed in its forming position on the engraving 17 of the two handling devices 2 and 2 'to the impact and during the impact of the impact tool and held at both ends. After striking and releasing the impact tool from the workpiece 10, the workpiece 10 is handled jointly and synchronously by the two handling devices 2 and 2 'according to the stored further handling routine. First, the workpiece 10 is released, as already explained with reference to FIG 3, and then either processed again in the first engraving 17 or immediately implemented in the second engraving 18 of the tool 12. After the conversion of the workpiece 10 in the second engraving 18 is again a forming step. After the shock release, the further common synchronous handling of the workpiece 10 is again initiated at an adjustable time during or at the end of the impact movement. It can now again together and synchronously the workpiece from the two handling devices 2 and 2 'are released in the second engraving 18 and possibly re-inserted into the engraving 18 for a repeated processing or the workpiece 10 can equal to the storage device 42 for the finished formed workpiece 10 are implemented.

For the handling devices 2 and 2 ', in addition to the embodiments described with reference to FIGS. 1 to 5, other manipulators or industrial robots may also be used, for example those mentioned above Handling devices according to DE 42 20 796 A1 or DE 100 60 709 A1. In addition to the described handling movements, additional or alternative handling movements may also be provided by the handling devices 2 and 2 'with or without a workpiece 10. The spacing of the gripping devices, for example the distance vector A in FIG. 4, is generally dependent on the length or along this distance measured dimension of the workpiece and remains constant during the synchronous common handling in the rule. But it can also be a volume or shape change of the workpiece after the forming process, in particular an elongation of the workpiece, are taken into account by the handling devices 2 and 2 'change their points of attack on the workpiece, for example, on the outside of an elongation of the workpiece. Furthermore, the movement trajectories of the two handling devices can also deviate from one another in an adapted manner, for example in an offset or a correction, for example if the workpieces have different burrs or other different shape at the engagement areas. An error communication via the control device 43 makes it possible to interrupt the process in an impermissible deviation of the handling devices of the prescribed trajectory at a given time, in particular to stop the handling devices.

LIST OF REFERENCE NUMBERS

2, 2 '

handling device

3, 3 '

gripper

4, 4 '

carrier wave

5, 5 '

support means

6, 6 '

bearing part

7, 7 '

flexible element

8, 8 '

rotary drive

9, 9 '

joint

10, 10 '

workpiece

11, 11 '

actuator

12

die

13

impact tool

14, 14 '

pivot bearing

16, 16 '

transport means

17, 18

engraving

30, 31, 30 ', 31'

jaw

32, 33, 32 ', 33'

gripping levers

34, 34 '

pivot bearing

35, 35 '

Angreiflager

41

Providing device

42

Bin Setup

43

control device

50, 50 '

supporting part

51, 52, 51 ', 52'

attachment portion

53, 53 '

connecting rod

M, M '

front axle

N, N '

rear axle

A

impact direction

B, C

axis

D, E

swivel axis

F

swivel axis

G

gravity

R

axis of rotation

Claims (23)

1. Method for forming at least one workpiece, wherein

   a) the workpiece (10) is placed in a forming position on a first tool (12) of at least two tools (12, 13) of a forming machine, preferably a percussive forming machine, in particular a forging hammer or a screw press or a crank press, wherein the tools are preferably forming die tools for the closed forming of the workpiece,

   b) the tools (12, 13) of the forming machine are moved relative to each other,

   c) the workpiece is shaped between the tools and

   d) the two tools are then relatively moved away from each other, and

   e) at least one handling device (2) begins to lift the workpiece (10) from the first tool (12) at a lift-off point,
   characterised in that

   f) a trigger point is detected at which, during the movement of the tools relative to each other, the relative position (x) of the tools (12, 13) adopts or has reached a predefined or predefinable reference position (xR), and

   g) the lift-off point is determined contingent on the trigger point.
2. Method according to Claim 1, wherein the lift-off point for the at least one handling device is chosen or determined in such a way that it does not occur prior to a forming point at which the forming of the workpiece between the tools is completed or prior to a reversal point at which the direction of the movement of the tools relative to each other is reversed and/or wherein the lift-off point for the at least one handling device is chosen or determined in such a way that it occurs at a predefined or predefinable time lag after the forming point or after the reversal point, wherein in particular the time lag between lift-off point and forming point or reversal point is between 0 ms and max. 300 ms and/or max. ¾ of the time required for the moving apart of the tools, in particular between 0 ms and max. 100 ms and/or max. ¼ of the time required for the moving apart of the tools, preferably between 0 ms and max. 50 ms and/or max. 1/8 of the time required for the moving apart of the tools, and/or is chosen contingent on a predefined tool contact time.
3. Method according to one of the previous claims, wherein the first tool is essentially fixed to an external framework such as a frame of the forming machine or the floor, and the relative movement and relative position is the movement and position of the second tool relative to the external framework
4. Method according to one of the previous claims, wherein the at least one handling device places the workpiece in its forming position on the first tool and/or where the at least one handling device holds the workpiece securely between the tools in its forming position while it is shaped.
5. Method according to one of the previous claims, wherein the workpiece is shaped between the same tools in at least two forming steps, the workpiece being raised from the first tool by the at least one handling device after one forming step and then replaced in the forming position on the first tool for the subsequent forming step, in particular in order to ventilate it by means of a fan.
6. Method according to one of the previous claims, wherein the workpiece is shaped in at least two forming steps between different tools or tool zones, the workpiece being raised from the first tool by the at least one handling device after one forming step and then placed in another tool zone on the first tool or in the forming position in another tool for the subsequent forming step.
7. Method according to one of the previous claims, wherein after the forming step or after the last forming step each workpiece, after being lifted from the tool or tool zone, is transported by the at least one handling device to a delivery device and set down there.
8. Method according to one of the previous claims, wherein at least one control device is provided, controls the movements of the at least one handling device, and calculates the lift-off point contingent on the trigger point, as well as initiating a lifting movement of the handling device at the calculated lift-off point, the control device preferably transmitting a start signal to the at least one handling device at a starting point and the at least one handling device commencing a lifting movement after receiving this start signal and lifting the workpiece at the lift-off point.
9. Method according to Claim 8, wherein at least one position detection device is provided, which transmits a trigger signal to the control device at the trigger point when the relative position of the tools reaches the reference position and at which the control device calculates the lift-off point contingent on the entry point of the trigger signal, the position detection device preferably comprising a position switch assigned to the reference position or arranged on the reference position, which switch changes its switched state upon activation by one of the two tools, a change in the switched state of the position detection device being used as a trigger signal or trigger point.
10. Method according to Claim 8, wherein at least one position detection device is provided, which measures the position of the two tools relative to each other continuously and/or at certain measuring points and supplies the control device with an appropriate position measuring signal or an appropriate position measured value and wherein the control device compares the position measuring signal or the position measured value with a reference signal or reference value corresponding to the reference position and uses the correlation of the position measuring signal with the reference signal or of the position measured value with the reference value as a trigger point and calculates the lift-off point from this.
11. Method according to one of the previous claims, wherein at at least one relative position of the tools, preferably the reference position, the relative speed and/or relative acceleration of the two tools is calculated and the lift-off point is determined from the trigger point contingent on the calculated relative speed and/or relative acceleration of the two tools.
12. Method according to one or more of the previous claims, wherein the lift-off point is determined from the trigger point, in that a predetermined delay time is added to the trigger point or allowed to expire or wherein the control device calculates the starting point for the start signal by letting expire or adding the predetermined delay time to the trigger point and the lift-off point ensues from the starting point in an unequivocal manner, generally through the addition of the signal runtime and signal processing time of the start signal for the handling device.
13. Method according to Claim 12, wherein the delay time is contingent on the progression of at least one relative linear momentum with the movement of the tools relative to each other and/or is or becomes predetermined contingent on an adjusted or adjustable deformation energy.
14. Method according to one of the previous claims, wherein the reference position is or becomes predefined for the tools contingent on the temporal progression of the relative movement of the two tools and/or contingent on the deformation energy for shaping the workpiece or on a variable unequivocally correlated with the deformation energy.
15. Method according to one of the previous claims, wherein the deformation energy for shaping the workpiece or a variable unequivocally correlated with the deformation energy can be adjusted to one of at least two different values and the reference position for the tools is ascertained contingent on the adjusted value of the deformation energy or the correlated variable.
16. Method according to one of the previous claims, wherein the reference position for the tools is or becomes predefined in such a way that the sum of the signal or data runtimes and signal or data processing times at least required to calculate the lift-off point from the trigger point is smaller than the time interval of lift-off point and trigger point and/or wherein the reference position corresponds to the relative position of the tools lying furthest away from each other, or wherein the reference position is between the relative position of the tools lying furthest away from each other and the relative position of the tools lying nearest to each other.
17. Method according to one of the previous claims, wherein the workpiece is manipulated by at least two handling devices at least on being lifted off, the movement and positions of the handling devices being controlled or regulated automatically and in coordination with each other.
18. Method according to one of the previous claims, wherein the lift-off point is taught or adaptively calculated in that the relative position of the tools at the lift-off point is determined and the lift-off point is modulated to a desired value, in particular by modulating the delay time after the trigger point or by modulating the reference position.
19. Method according to one of the previous claims, wherein tinder material is blown out below the raised workpiece and/or from the first tool by means of at least one fan, with preferably a switch-on point for the fan being calculated contingent on the trigger point and preferably occurring after the lift-off point.
20. Device for forming at least one workpiece, in particular for use in a method according to one of the Claims 1 to 19 or for carrying out a method according to one of the Claims 1 to 19, comprising

    a) at least one forming machine, preferably a percussive forming machine, in particular a forging hammer or a screw press or a crank press, with at least two tools that can be moved relative to and away from each other for shaping a workpiece placed in a predefined or predefinable forming position between the tools, the tools being preferably forming die tools for the closed forming of the workpiece,

    b) at least one handling device for manipulating the workpiece,

    c) at least one control device for controlling or regulating the movements and positions of the handling device(s), characterised in that the device comprises

    d) at least one position detection device for detecting a trigger point at which, during the movement of the tools relative to each other, the relative position (x) of the tools (12, 13) adopts or has reached a predefined or predefinable reference position (xR) and that

    e) the control device is configured in such a way that it determines a lift-off point contingent on the trigger point and controls the at least one handling device (2) in such a way that the at least one handling device begins to lift the workpiece (10) from the first of the tools (12) at the lift-off point.
21. Device according to Claim 20, wherein each handling device comprises

    a) at least one gripping device with at least two gripping elements that can be moved relative to each other for gripping the workpiece,

    b) at least one carrier device, to which the gripping device is or can be attached, and

    c) at least one transport device for transporting the carrier device with the gripping device.
22. Device according to Claim 21, wherein the carrier device and the transport device are flexibly connected to each other in a flexible state and are essentially rigidly connected to each other in a rigid state, at least in one direction in space and/or in each rotational position of the gripping device and/or the gripping element(s), in that either the carrier device and the transport device are connected to each other via at least one connecting element that is flexible in the flexible state and rigid in the rigid state or the carrier device and the transport device are connected to each other in the flexible state via at least one flexible element and are essentially braced together or against each other in the rigid state via at least one supporting device by bridging of the flexible element.
23. Device according to one or more of the Claims 20 to 22 with at least one fan for blowing out tinder material below the raised workpiece and/or from the first tool, with preferably each fan being switched on at a switch-on point by the control device and the control device calculating the switch-on point contingent on the trigger point and preferably after the lift-off point.

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